Many power systems have multiple generator sets for supplying electricity to external power loads. Often, these generator sets are connected to supply the power in parallel via a common bus. After one generator set is connected to the common bus, any additional generator sets subsequently connected to the bus should produce power matching the voltage, frequency, and phase angle of the power produced by the first generator set. This matching is also known as electrically synchronizing the generator sets. A better sync, results in a smoother transition and a lower shock on the generator and load.
An example of a power system that utilizes electrical synchronizing of multiple generator sets is described in U.S. Pat. No. 4,575,671 (the '671 patent) issued to Lee et al. on Mar. 11, 1986. The '671 patent discloses a method for synchronizing multiple motor-driven generators wherein each generator includes an associated position indicator that provides an indication each time the generator's rotor is at a predetermined rotational position relative to the generator's stator. The method includes connecting a first motor to an AC power source, and permitting the first motor to drive an associated first generator until the first generator produces a voltage having a desired frequency. The method further includes connecting the first generator to an output bus. The method then includes connecting a second motor to the AC power source, and permitting the second motor to drive an associated second generator until the second generator produces a voltage having a frequency and amplitude substantially equal to the amplitude and frequency of the output bus voltage. The method also includes comparing a time of occurrence of a position indication associated with the first generator with a time of occurrence of a second position indication associated with the second generator, and selectively disconnecting and reconnecting the second motor from the second generator until the times of occurrence are within a predetermined interval.
Although the method of the '671 patent may allow phase, frequency, and voltage matching based on rotor shaft position, it may be sub-optimal. That is, the system of the '671 patent, because it relies on the monitoring of electrical power produced by the multiple generator sets and on mechanical monitoring of the generators, may have synchronization time that is slower than desired.
The genset control system of the present disclosure addresses one or more of the problems set forth above.